16 research outputs found
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
A review of a decade of lessons from one of the world’s largest MPAs: conservation gains and key challenges
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordtribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British
Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos
Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds
for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for
all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data
have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fsh abundance, at
least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of
green turtle clutches (Chelonia mydas) is~20,500 and increasing and the number of seabirds is ~1 million. Animal tracking
studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fshes, elasmobranchs
and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles
travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater
video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be
as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and
respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats
to this MPA have been identifed, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fshing
activity, which considerably impact both reef and pelagic fshes.Bertarelli Foundatio